Last week I was lucky enough to fly halfway around the world to Istanbul with my friend and colleague, chef Angelo Sosa. He was invited by MSA (a gorgeous new culinary school in the heart of Turkey)
to lead a workshop for the students demonstrating liquid nitrogen applications in the kitchen. I accompanied him as sous for the week.
I was obviously excited-not only had I never been to Istanbul before, but this would be my first time working with liquid nitrogen. The city of Istanbul is beyond words-it has one of the richest and oldest cultures on earth and it shows in their culinary heritage and traditions. We arrived in Turkey without any expectations, good or bad, but at every step of the trip we were surprised with excellent food. Doner kebab, grilled squid, charred eggplant, deep fried mussels… everywhere we went, the food was not just prepared perfectly, but composed in its own unique Turkish way.
However, the purpose of our trip wasn’t to sample Turkish food; we were there to educate students about the uses of liquid nitrogen in the kitchen-and why not share the information here on Cooking District?
Most importantly, serious safety concerns need to be addressed before working with liquid nitrogen. Freeze burns-a real danger when working with LN-are the least of your worries. More dangerous are the possibilities of asphyxiation and explosion. As nitrogen transitions from liquid to gas form, it expands in volume by a factor of roughly 700 times. If you’re working with LN in a small unventilated space, the nitrogen will displace all of the oxygen in the room and will cause suffocation. Making the danger worse, your body continues to exhale CO2; when you are drowning or choking, panic is caused when you cannot expel CO2 from your system. When breathing pure nitrogen, your body does not activate the suffocation distress signals so when you do pass out…that’s pretty much it. The same expansion properties can make liquid nitrogen highly explosive when sealed in a container. LN is stored in what's called a ‘dewar.' It allows pressure to be lowered as the LN changes from liquid to gas and expands. If you put LN in a Thermos bottle and seal the top, the pressure will cause it to blow. And even if the shrapnel of a blown up Thermos bottle somehow didn't harm you, the explosive spray of liquid nitrogen is certainly a danger you need to avoid. For more complete notes on staying safe with LN, check out the LN primer on Cooking Issues
So what do you use it for? My favorite demo was the first one-a simple ice cream recipe made in the Kitchen Aid. The quicker you freeze your ice cream base, the more minute the ice crystals are and the smoother the final product is. Once the ice cream base has reached a somewhat cool temp (down from a simmer to cook the eggs), it’s placed in the stand mixer and then spun as LN is carefully poured into the bowl. Despite the incredibly low temperature of LN (-196ºC; -321ºF), it only has 15% more cooling capability than the same amount of ice at 0ºC. This means it still takes a lot LN to cool the ice cream down-but it comes together very quickly, and that’s the whole point.
We ran through a few other LN food concepts too. Popcorn makes for a fascinating LN application-after a quick dunk in the LN, you can eat it pretty much right away. Pop one in your mouth, let out a big breath and you get a nice puff of cool steam.
The last demo was a frozen chocolate fondue. Angelo loves to put big flavors to work in his food, and he found a great opportunity to do that with this dish. For this demo Angelo would usually add eastern chili peppers to create a chocolate fondue with a little molé homage. Our hosts introduced us to a local Turkish chili paste which we incorporated into the chocolate sauce. We’d dip skewers of fresh fruit into the spiced chocolate and then into the liquid nitrogen to freeze the exterior.
Not only is the presentation a total crowd pleaser, but the food is truly delicious. Using LN is not a case of doing something different for the sake of being different, but it really can provide superior results.